Hi everyone!
I want to build a cabinet containing 2 speakers to fit in the space directly below the TV. When I built the shelves I planned on building a pair of speakers to sit on either side of the television. Well, after the shelves I built a pair of the Wayne Parham
Four pi using jbl 2226h woofers for my basement system. They really are amazing and Im sure I will be disappointed with a small set of bookshelf speakers now. The space is 19” high, 14” deep, and 70” wide. Im considering 2 designs. The Michael Chua Osprey 12 and the Zilchlab delite 10 econowave.
https://www.ampslab-spk.com/2021/08/23/osprey12/
https://techtalk.parts-express.com/showthread.php?p=1639915#post1639915
I tried to link to them above. This will be mostly music streaming with some movie watching. Clear natural dialog is more important than impressive deep bass for the movie watching. I would like strong 80 hz or lower for satisfying musical playback though. I wont be using any sort of dsp for this system and would like to not need a sub. The room is 14 x 30 x 8’ and all hard surfaces except a thin area rug. Im guessing the osprey 12 is more of a sure thing as Michaels designs get alot of praise and I have the space to build each 12” woofer its own 100 liter sealed cabinet. What I like about the delite 10 is the constant directivity waveguide and the rheostat on the compression driver could be a nice feature. With this design I think I will need a vented enclosure which would likely require some experimentation to get sounding natural in the odd location they will be placed. I do intend to angle either design up enough to aim above the person sitting on the couch 15’ aways head.
All thoughts and opinions on how to get this right are appreciated!
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My plan is to end up with something more resembling a storage cabinet than speakers. Either one long cabinet, which would be super heavy but look the best, or 3 smaller ones. If I use the 12” coax design I would likely build one box with a partition in the center and 3 grills on the front built to resemble cabinet doors with rattan mesh or something similar. The design using the wave guide would leave room for actual storage space in the center. I guess the real question is how high in frequency and at what rate should the roll off on the low end of the woofer begin to end up with natural dialog. Im guessing I need a good bit less bass response than typical, likely with roll off as high as 200hz.
OK, here's an interactive musical instrument chart including vocals and one for human hearing perception for you to learn about what all is required for when wanting the best of both, which basically 'says' you can't have your 'cake and eat it too' without some compromises.
The pioneers (W.E., Bell Labs) proved we ideally you want an 8" tri-ax for vocals, so can't even get started without compromise, though there's plenty of folk's who'll take issue/flat out disagree with this.
Regardless, for now, please familiarize yourself and maybe answer your own Qs and/or come up with a host of others now that we've focused the thread to likely be yet another unending debate on this subject. 😈😉
The pioneers (W.E., Bell Labs) proved we ideally you want an 8" tri-ax for vocals, so can't even get started without compromise, though there's plenty of folk's who'll take issue/flat out disagree with this.
Regardless, for now, please familiarize yourself and maybe answer your own Qs and/or come up with a host of others now that we've focused the thread to likely be yet another unending debate on this subject. 😈😉
Hi GM,
I guess I am missing something. I stated that I have 10 cu ft to work with, which should easily be enough to get good performance to 80hz which is the lowest bass I would like to sound powerful, falling off below that would be fine. These will be used in a position that will provide, I think 6db gain below whatever frequency the woofer radiation is omnidirectional. My biggest concern is keeping the bass from overpowering the rest of the vocal range. I think the bass response needs to be down 6db to compensate for the boundary gain, but Im not sure at what frequency. It seems the simplest route is to build boxes with very limited bass output that when placed on the floor against a wall sound balanced. Besides figuring out what the roll off of the bass should look like what other issues and compromises do I need to consider?
Thanks
I guess I am missing something. I stated that I have 10 cu ft to work with, which should easily be enough to get good performance to 80hz which is the lowest bass I would like to sound powerful, falling off below that would be fine. These will be used in a position that will provide, I think 6db gain below whatever frequency the woofer radiation is omnidirectional. My biggest concern is keeping the bass from overpowering the rest of the vocal range. I think the bass response needs to be down 6db to compensate for the boundary gain, but Im not sure at what frequency. It seems the simplest route is to build boxes with very limited bass output that when placed on the floor against a wall sound balanced. Besides figuring out what the roll off of the bass should look like what other issues and compromises do I need to consider?
Thanks
Greets!
Hmm, thought my first paragraph made plain the problem and the second a primary example with the rest to get you to go from there, but apparently not. 🙁
Yes, well aware you have enough net volume (Vb) to achieve the 80 Hz necessary gain BW/peak SPL, but in doing so, you compromise high speech intelligibility unless you roll off the HF as required to compensate same as is done in cinema sound design.
This of course now compromises the video's total soundtrack playback because you don't have a cinema's horns, room acoustics to ameliorate all this, i.e. using a film video; with fingers spread, cup your hands over your ears to hear the tonal difference when the LF is rolled off and use EQ to find the best compromise of HF response.
Woofer goes omni below its baffle step frequency + any nearby boundaries are factored in, so somewhere below its ~60 Hz baffle step in 2pi space based solely on a 70" width setting close/on the floor and being only ~ 14" deep, call them in 1.0 pi space for simming purposes, i.e. may need to roll off as high as 500 Hz, the point where speakers were historically spec'd nominally flat from 250 - 2500 Hz (analog), 300 - 3000 Hz (digital) phone BW(s) and finally at 500 - 3000 Hz (Dolby?) for high speech intelligibility.
Re roll off (TBD), sealed with a roll off that ensures not running out of Xmax at desired peak SPL.
Then again, I'm way out of date electronics wise, so by now the HT's room EQ measuring system may dial all this in, making any design concessions moot.
Hmm, thought my first paragraph made plain the problem and the second a primary example with the rest to get you to go from there, but apparently not. 🙁
Yes, well aware you have enough net volume (Vb) to achieve the 80 Hz necessary gain BW/peak SPL, but in doing so, you compromise high speech intelligibility unless you roll off the HF as required to compensate same as is done in cinema sound design.
This of course now compromises the video's total soundtrack playback because you don't have a cinema's horns, room acoustics to ameliorate all this, i.e. using a film video; with fingers spread, cup your hands over your ears to hear the tonal difference when the LF is rolled off and use EQ to find the best compromise of HF response.
Woofer goes omni below its baffle step frequency + any nearby boundaries are factored in, so somewhere below its ~60 Hz baffle step in 2pi space based solely on a 70" width setting close/on the floor and being only ~ 14" deep, call them in 1.0 pi space for simming purposes, i.e. may need to roll off as high as 500 Hz, the point where speakers were historically spec'd nominally flat from 250 - 2500 Hz (analog), 300 - 3000 Hz (digital) phone BW(s) and finally at 500 - 3000 Hz (Dolby?) for high speech intelligibility.
Re roll off (TBD), sealed with a roll off that ensures not running out of Xmax at desired peak SPL.
Then again, I'm way out of date electronics wise, so by now the HT's room EQ measuring system may dial all this in, making any design concessions moot.
Can you stick one or both of your Four Pi's in that location and measure/listen to see what you have/like/dislike? You'll need to ignore some directivity related issues obviously, but the overall balance should be representative.
Speculating and planning only get you so far. Sometimes it's easier to just throw something together and take a listen/measure.
Speculating and planning only get you so far. Sometimes it's easier to just throw something together and take a listen/measure.